Hydkaulic brake



my y 3,6353@ El). NETTNSTRCDh/l HYDRAULI C BRAKE Filed June l, 1925 4 Sheets-5heet l In d@ mib? Jlly 12 f 1927' D. NETTENSTROM HYDRAULIC BRAKE Filed June.

1925 4 Sheets-Sheet 2 251 de V55-071 July 12 1927 D. NETTENSTROM HYDRAULI C BRAKE Filed June 1925 4 sheets-sheet 5 I7@ Mefzfof July 12 1927. 1,635,383

D. NETTENSTROM HYDRAULIC BRAKE Filed June l 1925 4 Sheets-Sheet 4 Patented July 12, 1927 DAVID NETTENSTROM,

0F CHICAGO, ILLINOIS.

HYDRAULIC BRAKE.

Application filed June 1, 1925. Serial No. 33,868.

The purpose of this invention is to provide an improved brake mechanism of the hydraulic type especially adapted for use on motor-driven road vehicles. It consists of certain features and elements of construction in combination as herein shown and described and as indicated by the claims.

In the drawings Figure 1 isa side elevation of an automobile wheel and axle with its associated trame structure and with a brake mechanism embodying this invention applied thereto.

Figure 2 is a transverse section on a larger scale taken as indicated by line 2 2 on Figure 1.` v

Figure 3 is a vertical section taken as indicated at line 3 3 on Figure 2, and showing the interior of the casing with the gearsv removed.

Figure 4 is a vertical section taken as indicatedat line 4 4 on Figure 2 showing the driving and pumping gears in operative relation.

Figure 5 is a vertical detail section taken as indicated at line 5 5 on Figure 4.

Figure 6 is a detail section taken as indicated at line 6 6 on Figure 5.

Figure 7 is a `detail section taken as indicated at line 7 7 on Figure 6.

Figure 8 is an elevation of a vehicle wheel and associated parts showing a. modified form of brake device applied thereto.

Figure 9 is a horizontal section taken as `indicated at line 9 9 on Figure 8.

Figure 10 is a vertical detail section taken as indicated at line 10 10 on Figure 9.

Figure 11 is an inside view of the casing of the device shown on Figure 8 with the pumping gears removed, but showing the valve control devices.

Figure 12 is a view similar to Figure 11 showing the gears in operative position.

Figure 13 is an end elevation taken partly in section as indicated at line 13 13 on Figure 12.

Figure 14 is a top plan View of the device shown in Figure 8. e i

The brake device which is the subject of this invention is in the nature of a iluid pump of the gear type having an in-built fixed portion of the running gear and connecting the moving parts of the pump with the vehicle wheel, the control of the fluid by this valve may be utilized to produce a braking effect upon the rotation of the wheel which will operate more smoothly and much more quietly than the ordinary friction brake as applied by expanding or contracting bands.

Referring to drawings, Figure 1 shows a vehicle wheel, A, with its fixed tubular axle, B, indicated in section and its drive shaft, C, carried within said axle, B, in accordance wit-h common automobile practice. The brake device is shown more in detail 1n Figure 2 and comprises a casing, 1, with a cover plate, 2. The casing, 1, is anchored to a flange, B1, of the axle, B, and carries concentrically with respect to said axle a driver gear, 3, meshing with a pinion, 4, through which a second small gear, 5, is driven. The gears, 4 and 5, constitute, a gear pump, the casing wall being snugly fitted to the teeth of said gears at 6 andl 7, and the lateral wall of the casing having inlet and outlet ports 8 and 9, respectively, which are connected by the bypass, 10, formed in the cast casing, l. Assuming that in the forward travel of the vehicle the driver gear, 3, turns with the wheel, A, in the direction of' the arrow, a, on Figure 4, it will be seen that the gear, 4, will turn in the direction of the arrow, I), and the gear, 5, in opposite direction as indicated in the arrow, c. If the cavity of the casing, 1, be filled with oil or other suit-able liquid, the liquid will be swept by the gears past the close-fitting portions, 6 and 7, of the casing wall to the outlet, 9, through which it will be expelled because the intermeshing teeth of the gears, 4 and 5, will prevent flow in any other direction. It may be understood that the lateral faces of' the gears are flat and fit closely against the casing walls. The liquid flowing from the o-utlet, 9, is Jforced through the ley-pass, 10, and returns vthrough the inlet, 8, to the cavity of the casing, 1, to be swept around the `same circuit repeatedly by the gears, 4 and 5.

A valve in the form oi` a simple turncock, 11, controls the by-pass, 10, and may be operated by any suitable linkage such as a crank arm, 12, and link, 13, extending to a foot-pedal orv hand-lever (not shown) within convenient reach of the driver.- When the valve is fully open as shown in Figure 2, it will not interfere with Vtliefree How of oil or liquid around the circuit indicated, but by partially closing the valve this flow may be tlirottled to suoli anexvtent as to impose consideiable load upon the driver gear, 3, and since this gear is directlyronfVlr nected to the wheel, A, this load will tend to retard the wheel. By t'ullyclosing the valve, 11, t-he flow of oil may be checked, except as to any slight leakage which may exist in the pump mechanism, with the result'that the gear, 3, will be stopped, and the wheel, A, correspondingly arrested. V

For convenience the wheel, A, and gear,3, are coupled by interengagin'g teeth which ai'e formed respectively on an annular portion, 3a, on the gear and an annular ilange,

' 14, on the hub flange, 15, ot' the whe-el. This tooth formation permits the wheel to be readily removed from the tapered rend of the drive shaft, C, without disturbing the brake In this form of the device the gear, 3, is-

merely a driving gear, and is not relied upon for any pumping actiong'th-e casing, 1, is litted around the gear, 3, with clearance and lateral clearance is provided at the point where said gear meshes with theV pinion, 4, by ythe formationof a vertically extended channel, 19, in the ca'singrwall, the inlet, 8, being shown opening into saidv channel.

This also gives ample storage space Vfor 'a' suitable quantity of *oil orliqnid, so that the'pumping systeinvinay be kept well 'filled at ,all times; incidentally the oilwill -keep the gears thoroughly lubricated, thus-avoiding any rapid wear of the parts. Preferably to iiisurea close tit between the gears, 4

and5, and the vcasing walls, I provide sliimA plates,-2O and 21, at opposite sides of the gears, and fitted to conform to the casing,

1, as shown in Figure As the plates next to the gearswear away, they may be tightened up by the vinsert-ion of additional thin sheets `back of them next to the casing walls, and may be finally replaced with new shimplates to keep the pumping-parts-subf stantially oil-tight at these surfaces.

' leads ,romthe by-pass, 1 p tween the outlet9, and the valve, l11. .The

To avoid undue shock to thef'mechanism if the brakes should be applied suddenly by complete closure of the valve, 11, a relief valve, 22, is'mounted in a pocket, 23, in-y position to controla small port, 24, which 0, at a point be' port, 24, admits the -oil to the pocket, 23, and to a passage, 25, leading forward past the valve, 11, and back into the channel, 19, inthe casing, l1, y.as Yindicated in F igur-es 5, 6 and'7.' 'The valve, 22, is held normally seated by a spring, 26, which is stoppedv against a plug, 27, screwed into the end .ot' the pocket, `The spring, 26, is chosen of such strength that it will yield as soon as the back pressure in tlie'by-pass, 10, -eX- oeds a. safe value; the passage, 25, is small enough, however, so that the opening of the valve, 22, will notv wholly `neutralize the braking action, but will tend lto* prevent absolute locking of the wheel, A, or breakage ofitlieteeth of the .gears 1in .the casing, 1.

Figures 8 to 14 show a :modified vform of the invention in which the casing, 30, and its cover plate, 31, are of symmetrical outline, and the gearing constitutes aY pair of gear pumps. Tliecentral driver gear, 32, is, closely iitted between the walls, 33 .and.34, Vof the casing and meshes with two pinions, 35 and- 36, each of which runs in close iitting engagement-with a roundedend portion, 37, of the casing, 30. Thus, the driver gear, 32,

and either'ot the pinions, 35 and v36, forms a pumping device; and for each of rthese pumps ahy-pass, 38, is provided inthe casing casting. .Above and below the intermesliing teeth of the gear, 32, andeach 'of the pinions, ports, 39, lead to the by-passes, 38, one port of each pair serving as lthe outlet and the other as the iinlet, depending upon which direction :the gear, l32 is turned by the road wheel, A, 'to whichit is attached.

Each by-pass, 38, is provided with a control valve, 40, and these' valves are connected lfor simultaneous operation by. :any suitable means. The drawings show each valve iitted with a -small gear or pinion, 41, which meshes with a vertically slidable rack bai',

42, whoseupper end is engaged with one .end

of a rocker arm, 43, on va rock shalt, 44,.'which penetrates the casing wall and carriesIv an operating karm, 45, outside the casing. The arm, 45,.is coupled'wii-th'any suitable voperating` mechanism (not shown) as by a link member, 46. lI have not shown any reliefv valve applied to this form olf the invention,

llo

but it may be yunderstood that such valves might Aeasily be provided for in substantiallyv the same manner as in the' construction previously described. The particular 'ad-V vantage of the ni'odilied form is that it disA tributes the strain over morer'teetliy of the ifm large gear, 32, and correspondingly reduces the unit pressure of Vthe oil in the by-passes, 38,' and throughout-`thecasing `during the ap-A plication of the brake.

lIt maybe noted that in this modified con! struction the central gear, 32, is interlocked with the wheel, A, by means of toothed anJ nular members, 47 and 48, yandlthatthe gears,

35 and36, are laterally packed bymeans of Eli shim plates, 49, arranged in the same general manner as in the first described form. 'I'o prevent leakage of oil around the rock shaft, 44, any suitable form of packing gland such as that indicated at 50 may be fitted into the casing, 30.

I claim 1. A brake f'or a vehicle wheel comprising a relatively fixed fluid-tight casing, a pair of intermeshing gears journaled therein operatively connected for rotation by the vehicle wheel, the casing wall being formed with non-adjacent portions fitted snugly around segments of said gears respectively and having an inlet and an outlet separated from each other by the intermeshing teeth of the gears and connected by a passage for fluid, together with a valve controlling the flow through said passage.

2. A brake for a vehicle wheel comprising a relatively fixed fluid-tight casing, a pair ofl intermeshing gears snugly fitted in the casing and dividing it into two chambers, means operatively connecting said gears for rotation by the vehicle wheel, a by-pass connecting the two chambers of the casing and a control valve in the by-pass.

3. A brake device for a vehicle wheel coniprising a relatively fixed fluid-tight casing, a pair of intermeshing gears journaled therein and connected for rotation by the vehicle wheel, the casing wall Abeing formed with non-adjacent portions fitting snugly around segments of said gears respectively and having an inlet and an outlet each disposed between said non-adjacent portions with a bypass connecting said inlet and outlet and a control valve in the by-pass.

4. In combination with a vehicle wheel and axle, a gear operatively connected to the wheel, a fluid-tight casing fixed with respect to the axle, a rotary pumping device in the casing arranged to be driven by the said gear together with fluid inlet and outlet ports in the casing and a by-pass connecting them to form a path for fluid with a control valve in the by-pass for retarding the wheel by blocking the flow therethrough.

5. A brake device comprising in combination with a vehicle wheel and a fixed axlev therefor, a casing fixed with respect to said axle, a driver gear 1n the casing connected for rotation by the vehicle Wheel, a

i pair of' driven gears meshing with the driver means for controlling the movement of fluid through said pumps.

6. In the combination defined in claim 5, passages formed in the casing providing a closed circuit for the fluid handled by said pumps, said valve means controlling the flow through said passages.

7. In the combination defined in claim 5, inlet and outlet ports being formed in the casing at respectively opposite sides of the intermeshing port-ions of the gears whereby said interineshing portions form a partition between the inlet and outlet of each pump, a by-pass formed in the casing connecting the inlet and outlet of each pump and'valve means controlling said by-passes.

8. In the combination defined in claim 7, said valve means comprising separate valve members for the by-passes and inter-connected operating means for said valve members arranged to move them simultaneously for closing or opening both valves together.

9. In the combination defined in claim l, said gears having flat faces and fiat shim plates disposed against the fiat faces of the gears in contact with the segments to which the casinor is snugly fitted.

1G. A brake device comprising in combination with a vehicle wheel and a fixed axle therefor, a gear pump having its casing fixed with respect to the axle, a gear in the casing concentric with the vehicle wheel and formed with an annular toothed portion extending from the casing toward the wheel, said wheel having an intermembering toothed portion to provide a driving engagement for Said gear, the casing being provided with an outlet and an inlet for the fiuid with a bypass connecting them and forming a closed passage for fluid handled by the pump, together with a control valve in the passage for reducing or blocking said flow.

ll. In the combination defined in claim V5, the driver gear being co-axial with the vehicle wheel and having an annular p0rtion extending through the casing toward the wheel, means on the wheel engaging said annular portion of' the gear and packing means around the annular portion in the casing.

l2. A brake device comprising in combination with a vehicle wheel and a fixed axle therefor, a fluid-tight casing fixed with respect to the axle, a rotary pumping device in the casing having a driving member concentric with the wheel, said driving member including an annular portion extending through the casing toward the wheel, means on the wheel engaging said annular portion and packing means between said annular portion and the casing for keeping the casing fluid tight.

DAVID NETTENSTROM.

CTI 

